1. Field of the Invention
The present invention relates to stabilized pharmaceutical compositions.
More particularly, it is concerned with stabilized therapeutic compositions for circulatory diseases containing a dihydropyridine derivative as an active ingredient.
2. Description of the Prior Art
Dihydropyridine derivatives which are an active ingredient of the compositions of the invention are disclosed in Japanese Patent Laid-Open-to-Public No. 60-89420 for preparative process and pharmacological effects in the circulatory system. However, technique for stabilizing the compounds in long-term storage has not been known.
The dihydropyridine derivatives used as the active ingredient of the invention are apt to be much decomposed in solid pharmaceutical preparation, and long-term storage of the preparation is a problem in stabilization.
It is an object of the invention to provide stabilized pharmaceutical compositions.